Require Police to Get a Warrant to Search ALPR Data

This post was co-written by Andi Cao, an EFF legal intern. Automated license plate readers (ALPRs) are mass surveillance. They photograph every passing car and log where and when it was captured, building a searchable record of where nearly everyone drives. Cities should not buy them, and cities that already have them should shut them down. Where these systems still operate, courts and state legislatures must reduce their harms by (among other things) requiring police to get a warrant before searching stored ALPR data. A warrant requirement would not make mass surveillance acceptable, but it would require police to justify a search to a judge before accessing records of people’s movements. Without this independent judicial check on police power, officers have been searching this data for improper reasons (many exposed by EFF) that violate our fundamental rights. A warrant requires a judge to find probable cause and specificity—many warrantless police searches of ALPR data lack both. Of